May 6, 2013

Duke University Engineers Create Invisibility Cloak With 3D Printer

Duke University engineers are developing a way for you to create your own visibility cloak with a 3D printer.

Three-dimensional printing is growing in popularity, and the cost for a MakerBot Replicator 2 is now just $2,199. Scientists are also working harder and harder to turn Harry Potter's invisibility cloak into a reality.

A group wrote in the New Journal of Physics in March about how they developed a new cloak that is able to hide three-dimensional objects from microwaves in their natural environment. This cloak is just micrometers thick, and is the closest thing yet to Harry's infamous hiding tool.

Researchers have now published in the journal Optics Letters that anyone who has a 3D printer may be able to make a plastic cloak overnight.

Yaroslav Urzhumov, assistant research professor in electrical and computer engineering at Duke's Pratt School of Engineering, said he and his team created a small cloak with a 3D printer that looks like a Frisbee disk made out of Swiss cheese. Algorithms helped determine the location, size and shape of the holes, helping to deflect microwave beams.

The disk cloak has an open area in its center where the researchers placed an opaque object. When microwave beams are aimed at the object through the side of the disk, the cloak makes the object appear as if it is not there.

"The design of the cloak eliminates the 'shadow' that would be cast, and suppresses the scattering from the object that would be expected," said Urzhumov in a statement. "In effect, the bright, highly reflective object, like a metal cylinder, is made invisible. The microwaves are carefully guided by a thin dielectric shell and then re-radiated back into free space on the shadow side of the cloak."

The researchers believe that one day, in the not-so-distant-future, they will be able to create a cloak that is able to reflect higher wavelengths, such as visible light.

"We believe this approach is a way towards optical cloaking, including visible and infrared," Urzhumov said. "And nanotechnology is available to make these cloaks from transparent polymers or glass. The properties of transparent polymers and glasses are not that different from what we have in our polymer at microwave frequencies."

He said that their technique could be used to help create much larger objects with a 3D printer.

"Computer simulations make me believe that it is possible to create a similar polymer-based cloaking layer as thin as one inch wrapped around a massive object several meters in diameter," he said. "I have run some simulations that seem to confirm this point."